I have Sabertooth 990FX rev. 1 / 1100T combo and can get 1866MHz, but have to OC w FSB. With the FSB @ 200, the highest memory freq option is 1600MHz. ( I have 4x4GB)

It sounds like you have your FSB @ 232? The main thing you want to consider for your ram to run @ 1866 is to have your NB @ 2800+ MHz, so change your FSB to 236 and select Mem Freq 1888MHz, NB Freq 2832 MHz, select HT Link 1888MHz. You may want to increase your CPU/NB voltage to run 2800MHz ( I have mine @ 1.35v). Reboot and let me know.

Oh yeah, you'll have to go to DRAM timings and manually set your ram timings (9-10-9-28-?? 2T for your ram I think)

The issue is I do not know how to set timings or adjust the pertinent voltages. The system runs stable on auto settings of course....but whats the point of paying extra for 1866 when it defaults to 1333?

What irritates me is Asus advertises the mb able to run 1866. There should be no tinkering in that case, nevermind manually entering in timings etc... I am sort of stuck right now.

I know this thread is old but I'm hoping someone will see it and respond. I'm in the same boat, same motherboard, FX 8350 CPU, trying to get my G.Skill 1866 MHz memory to run at 1866. I have the Sniper Series, 2 x 8 config.

I'm wondering if there was a resolution to this OP's issue. From all my research, 1866 is native to the FX 8350, so that shouldn't be an issue. But, AMD claims support for two DIMMs of DDR3-1600 per channel. Two DIMMs of DDR3-1866 on a single channel will be down-clocked to 1600. What's that all about??? And, the Sabertooth 990FX specs say it supports up to 1866 memory; but is that ONLY with overclocking?

G.Skill says to change the timings, voltage, etc. and it should run at 1866. It might work. But, I'm wondering if it's maybe better for the entire system to use memory that runs at appropriate speed without overclocking. And, CPU-Z says my memory is "single channel", timing 11-11-11-28 .... that's wrong! Mine is 9-10-9-28, dual channel. And installed in A2 and B2.

I have an ASUS Sabertooth P67 and originally had trouble getting my Corsair Vengeance Pro 1866 running at proper speeds. It all had to be set manually within the BIOS, doing so automatically overclocks the CPU multiplier and voltage. When I choose the profile (manual or XMP) it gives me a 9-10-9-26 timing but I bump the 26 to 27 since the memory's sticker says 27. I too run in A2 and B2. Upon original install, I don't recall specifically, I don't think my system would boot with the memory in A1 B1.

I did notice in BIOS under one of the preset profiles that none of the available memory speeds in the drop down menu are correct, ie 1648 or so instead of 1866 and so forth. It's all above my head. I wish it were a bit more user-friendly for a newb like myself so I find it shocking that ASUS hasn't made this any easier/simpler for their newer line of Sabertooth motherboards.

Well, I got my RAM running fine using DOCP profile. But still was showing only 8 of my 16 GB of memory, and running in single channel vs dual channel. After almost 2 weeks of intensive research, trying every suggestion, I found numerous people who had similar problems and "fixed" it by re-seating the CPU. Some even found bent pins and still resolved their memory problems.

I finally pulled my CPU and found several bent pins in one corner; tried to straighten them with a tweezers, re-installed and couldn't even post ... only fans running and the red CPU light. Tried a 2nd re-install, same thing. I've ordered a replacement CPU, coming tomorrow. Hoping it will fix everything!

I just solved this problem in and in wanting to help out anyone I could i wanted to reach out and say i was able to set the timings, voltage and ram speed to be recognized as 1866mhz on my Gskill ram as well.